manufacture/mrp_bom_note/views/mrp_bom_view.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
    <data>

        <record id="mrp_bom_form_view_inh_notes" model="ir.ui.view">
            <field name="name">mrp.bom.form.view.inh.notes</field>
            <field name="model">mrp.bom</field>
            <field name="inherit_id" ref="mrp.mrp_bom_form_view"/>
            <field name="arch" type="xml">
                <page string="Properties" position="after">
                    <page string="Notes">
                        <group>
                            <field name="notes" nolabel="1" />
                        </group>
                    </page>
                </page>
            </field>
        </record>

    </data>
</openerp>